Heres what I do and it seems to work pretty good. I have 2 rechargeable battery packs. A regular conroller, my viking, and 1 pnc cable hooked to my xbox. I have my regular controller always plugged into the xbox via pnc, and it charges. When the battery in my viking goes dead i put it in the controller, and it makes it so you almost never have an uncharged battery.
